1. Field of the Invention
The present invention relates to a rotary connector for supplying electric power to an air bag or the like. More particularly, the present invention relates to a rotary connector used at a pad of a steering wheel of an automobile.
2. Description of the Related Art
A conventional rotary connector is commonly used for supplying electric power by incorporating a flat cable usually wound in a spiral fashion. Recently, a technique has been implemented in which when an accident occurs, an air bag pops out to protect the driver from the impact. This type of air bag, particularly the one provided at the pad of the steering wheel, requires electric power to be supplied from the vehicle side through a rotatable portion of the steering wheel to the inflater of the air bag system mounted on the pad side.
A variety of this type of rotary connectors have been proposed. For example, Japanese Utility Model Mo. 1-161589 discloses a rotary connector called a cable reel. This rotary connector includes a stator housing, a rotor housing rotatably assembled to the stator housing, and a flat cable accommodated in a spiral fashion in a space defined by the stator housing and the rotor housing. The rotary connector further includes a cutter and a cutting element provided at an end of the flat cable, the cutter and cutting element being used to cut the flat cable. Also a rotary connector can be assembled at a neutral position thereof from which the steering wheel can be rotated by two rotations leftward and rightward, respectively. If the rotary connector is assembled off the neutral position by steering wheel can be rotated by two rotations leftward and rightward, respectively, from the neutral position.
However, the aforementioned conventional rotary connector suffers from the problem that even if the rotary connector is assembled correctly to the steering wheel, the cutter and cutting member used for cutting the cable still remain in contact with the flat cable and therefore may damage the flat cable.
An object of the present invention is to provide a rotary connector in which the flat cable is not damaged when the rotary connector is assembled correctly and the flat cable can be cut off easily if the user operates a steering wheel to which a rotary connector is assembled incorrectly.
Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
According to a broad aspect of the present invention, the rotary connector having a flat cable with one end thereof connected to a terminal strap and the other end thereof connected to a supporting member, the flat cable being in the shape of a spiral and being accommodated in a space defined by a stator housing and a rotor housing rotatably assembled to the stator housing, characterized in that the terminal strap is located between an inner wall of the stator housing and a guide disposed near the inner wall. The guide has a small-width strap with a curved surface in contact with the flat cable; and the flat cable is routed to pass between the inner wall of the stator housing and the small-width strap into the space in the stator housing.
The stator housing has a projection formed on the inner wall near the small-width strap. The stator housing also has a projection formed on the inner wall between the terminal strap and the small-width strap. The guide has a recess near a location facing the projection. The projection has an inclined surface on a side thereof remote from the terminal strap.